Cellular phones have gained wide acceptance among users and communicating over cell-phones outside the home and the office environments has created new needs. For example, the use of cell-phones in cars has raised several concerns such as security, convenience of use, sound quality and the like. Indeed, answering a phone call while driving has been proven to be distractive and drivers often loose their attention to the road, the traffic and to their surrounding. A driver may also find it unpractical to hold the cell-phone close to his ear when his hands are already busy steering the wheel or changing gears. In addition, the surrounding noise may disturb the user who may not hear well and/or may not be heard well. The resulting sound quality is poor and cars are thus not well suited for phone conversations.
Several solutions have been released on the market to free the user from holding the cell-phone so that some of the issues mentioned above can be solved. Hands-free kits for cell-phones are widely available and some common ones comprise a microphone and a speakerphone connected to the phone. The microphone and the speakerphone may be integrated into one system that the user can place on his ear and/or head or, alternately, both may be mounted on the interior of the car close to the driver. These hands-free kits permit to partially free the user from having to hold the phone on one hand and they permit to improve the sound quality on the other hand. Other kits may comprise a microphone and a dummy tape connected to the phone. During a phone conversation, the driver inserts the tape in his car tape player and the voice conversation may be rendered through the audio system coupled to the tape player, e.g. speakerphones at the front and back of the car. Since tape players are present in most cars, such hand-free kits may be used with any cell-phone and these kits make great use of the existing audio systems of the car. However such hands-free kits often need to be physically connected to the cell-phone and may not be so convenient if the driver needs to connect the kit to the cell-phone before answering a phone call or if the driver needs to manipulate various buttons before being able to take an incoming call.
U.S. Pat. No. 5,781,850, herein incorporated by reference, proposes a live voice device adapted to utilize in its operation the acoustic loudspeakers already existing in vehicles and connected to a radio receiver apparatus thereof. This document discloses a dummy cassette comprising electronic means adapted to handle the low frequency signals of a cellular telephone apparatus, a microphone, a magnetic transducer facing the reading head of a tape player of the radio receiver apparatus. A suitably sized cord connects the dummy cassette to the cellular telephone apparatus. However, the document discloses that this cord, which is intended for transmission of signals, can also be implemented by radio waves. In a disclosed embodiment, a mini transmitter could be housed in an extension coupled to the cellular telephone apparatus connector. The mini transmitter is tuned on a given frequency pre-set in the car radio receiver so that, when a telephone call is received, it is sufficient to press the corresponding tuning button for receiving the telephone call in live voice from the loudspeaker system of the car radio receiver.
A Bluetooth special interest group was formed to define and promote the Bluetooth technology. This group consists of employees of companies involved in Bluetooth who define together some of the technical requirements for Bluetooth products to ensure interoperability among products. Reference is made to one of the specification being drafted and reviewed by the Bluetooth SIG Car Profile Working Group, “Hands-Free Profile”, Oct. 22, 2002 by Jesus A G. Pulido, herein incorporated by reference. This draft seeks to define the protocols and procedures that shall be used by devices implementing the usage model of operating a phone via an in-car device. This working group is interested in all implementations of the hands-free profile that enable a car's embedded hands-free unit to be wirelessly connected to a cellular phone for the purposes of acting as the cellular phone's audio input and output mechanism, providing full duplex audio with possibly noise suppression, voice recognition and so on.